5
Patients and Methods
Study design was a consecutive interventional case series.
We conducted a retrospective chart review of all patients who underwent Ahmed
Glaucoma Valve implantation at The Hospital for Sick Children, Toronto, Canada from April
1, 1995 through April 30, 2000. The retrospective review of patient charts for this study was
approved by the hospital's Research Ethics Board. All surgeries were done by the senior
author (AVL) who was also present at almost all follow-up examinations. In all cases, the
indication for surgery was glaucoma not sufficiently controlled by medications and/or
previous surgery, or a concern that medications or other forms of surgery were not
appropriate.
Each patient was reviewed within the week prior to surgery, and daily for the first
three postoperative days as a minimum. Some were seen daily for up to two weeks
postoperatively whereas others slowly had their visits spaced out depending on their progress.
IOP was measured awake or under sedation or general anaesthesia using Tonopen (Mentor;
Norwell, MA, USA), Perkins applanation tonometer (only for some exams under anaesthesia)
or Goldmann applanation tonometer). Data samples were taken from postoperative
examinations done at 1 day, 1 week, 2 weeks, 1 month, 3 months, and 6 months after surgery,
and every 6 months thereafter. Examination under sedation or anesthesia was performed as
tolerated and indicated.
In the immediate postoperative period, patients received topical atropine combined
with topical steroids and antibiotic preparations that were tapered slowly over a 4-8 week
period. Hypotony, particularly in the presence of even slight anterior chamber shallowing,
was treated with cycloplegia. Patching was prescribed in some patients but success was
limited. Patients with uveitic glaucoma received an increase in their topical and oral (when
